Anti-biofouling methods are known in the art. US2013/0048877, for instance, describes a system for anti-bio fouling a protected surface, comprising an ultraviolet light source configured to generate ultraviolet light; and an optical medium disposed proximate to the protected surface and coupled to receive the ultraviolet light, wherein the optical medium has a thickness direction perpendicular to the protected surface, wherein two orthogonal directions of the optical medium orthogonal to the thickness direction are parallel to the protected surface, wherein the optical medium is configured to provide a propagation path of the ultraviolet light such that the ultraviolet light travels within the optical medium in at least one of the two orthogonal directions orthogonal to the thickness direction, and such that, at points along a surface of the optical medium, respective portions of the ultraviolet light escape the optical medium.
JPH11278374 describes that that in a dock facility, a contamination preventing means, acting statically for preventing contamination when a dock inside wall face and a hull outside face are in the atmospheric/submerged ambience, is arranged in the vicinity of the dock inside wall face. The contamination preventing means is provided with a photocatalyst reaction body arranged on the dock inside wall face and a light generating means generating either of ultraviolet or visible rays. For preventing the dock inside wall from contamination under the atmospheric ambience, it is irradiated by natural light such as sunlight or ultraviolet light from the light generating means. Then, a photocatalytic reaction is generated in the photocatalyst part carried by the photocatalyst reaction body, and an organic body as a pollutant adhering to the dock inside wall face and the photocatalyst reaction body is decomposed and purification is carried out.
U.S. Pat. No. 5,308,505 describes that bio fouling of underwater surfaces by marine organisms is prevented by irradiating the water with ultraviolet light and adjusting the intensity of the ultraviolet light so as to kill barnacle larvae to prevent their attachment to the underwater surface. The water is passed through a biocidal chamber having a source of ultraviolet light at an intensity of at least 4000 mu watts/cm2 and at a rate to provide a residence time of at least one minute on the biocidal chamber.